So, that blog post is by Tutanota who, as we're all aware, also offer a paid-for product. But there's a lot of difference between a paid-for product that will only respect your privacy if you pay for it (and even that is questionable) and a paid-for product that just does respect your privacy, even on their free tier.

And, as others have said, Meta have made little to no mention of several things about this paid-for model:

1. What about all the tracking that Meta do on non-Meta sites?
2. On Meta sites, there's very little mention of them not tracking you anymore - they're just saying (as far as I can see) that they're not going to serve you personalised ads anymore.
3. The pricing Meta are going to charge is clearly meant to deter people from taking the ad-free model up.

I don’t see how this is a problem.

The first problem is that logic may go against the GDPR. The second problem is that by having this plan they're essentially confirming they don't other user privacy.

Meta is Facebook, Instagram and WhatsApp right? Some people would argue it could harm your social life to not be on those, depending on your social circle of course. Now if it becomes lose friends or pay or lose privacy, this might not be an actual choice but a one made for you.

The other problem is when legislation makes privacy a right, you can't then have a company sell it to you. That's like a company charging you to vote because all voting booths happen to be standing in their buildings.

I might be wrong, but I think GDPR means in this scenario if you won't pay, you aren't consenting to the ads. Meta by GDPR standards should be blocking you, not forcing ads on you.

They can't create a implicit permission for it.